Front wheel bounce, looking for advice

[Heavy Armor]

So I didn't really get any time on the old tires because they were so past their expiration that the brand was written in hieroglyphics Therefore, I really can't say how they handled, but I have new Shinko 777's and I'm noticing a mild bouncing sensation when the front suspension has to work, like a quick "wub wub wub" before it settles down again. Tire pressure is at 32 lbs per the book, suspension was professionally rebuilt with Progressives, and I'm running around 8-8.5 lbs of air. Is this a normal sensation for a heavier bike, or an air suspension, or is there something possibly wrong with my tire? Seems like if it was out of round, mis-mounted, or unbalanced, the issue would be more persistent...?

[Nails]

My last unbalanced tire (front) showed up twice, at about 45 and at about 85. I was touring some national parks, so it sucked whether in the parks or between them. Just pop the wheel off and get it balanced at your local independent, who deserves the support. (Even though that guy didn't balance mine right in the first place -- his only screw-up so far. Check the bike before heading off on a long ride!)

[cushman eagle]

It could also be a tire that happened to be built out of round

[GrandpaDenny]

Bouncing after hitting a bump is indicative of worn-out shocks in a car, so I assume the same would be true of forks on a bike. Did the professional rebuilder leave something out, perhaps? It seems like lack of damping. What weight fork oil did they use? How does the bike sit at rest, does it seem to sit higher than before the spring replacement, the same, or lower? You shouldn't have to run any air pressure at all with Progressive springs, maybe a pound or two at most. 8 pounds of air with progressives would have the bike riding like a rock.

[Heavy Armor]

You shouldn't have to run any air pressure at all with Progressive springs, maybe a pound or two at most. 8 pounds of air with progressives would have the bike riding like a rock.

Maybe that's the reason I'm getting some bounce... the tires are having to do the suspension work? I had an old truck like that, previous owner had jacked it up just by adding more springs to it. The suspension wouldn't give, but the big tires would balloon instead and bounce.

[buzzcut]

I just went through a similar bouncy time. progressives, 7.5 fork oil, 34psi and 8 in forks. not enuf damping. I went to 15 weight. allelujah. was able to go up to 40 in the front which I have always preferred for over 40 years. and no air with the 15w. If I had gone 10, I would still need air for my taste. but 7.5 waaaay to bouncy for me.

[Heavy Armor]

I REALLY don't wanna have to pull the forks again to go up in oil weight... I don't suppose you can swap the oil while they're installed? I know there's the drain at the bottom... how feasible is it to pop the top of the fork, see where the fluid sits, then drain it and fill it back up?

[Nails]

I don't suppose you can swap the oil while they're installed?

Get some long clamps like you'd use to glue a door together. They fit along the fork inside the fairing.

Regarding fork pressure, note that this pressure ramps up over every bump as well as with temperature, like when giving the forks a good workout. This is much like tire air pressure, and those of us with TPMS can see how much tire pressures vary. My point being that I don't think getting too fussy with these dynamic pressures makes much sense. (Listed tire pressures are cold, perhaps emphasizing minimum pressure to keep the tire safely on the rim as much as traction.)

[gtem]

I just put on some Shinko 777HDs on mine as well, along with refreshing the fork oil up front (used 10W), I thankfully have not felt any weird issues, very happy with the tires so far.

The one time I've felt a low speed shake on a set of Shinko 712s on my old GS1100E was when I didn't seat the bead quite fully on the rim, but that was a consistent shake at 30-35mph nothing to do with bumps in the road, and I could physically see my problem.